v3.8.0.1
Equity Equity, ATM Program (Details) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended
Aug. 22, 2017
Aug. 21, 2015
Sep. 30, 2017
Sep. 30, 2017
Partners' Capital Account, Public Sale of Units Net of Offering Costs       $ 3
2017 ATM Program [Member]        
Equity Instrument Regulatory Filing Date Aug. 22, 2017      
Registration Filing Date   Aug. 21, 2015    
Common Units Aggregate Value $ 750      
Partners' Capital Account, Units, Sale of Units     72,857 72,857
Partners' Capital Account, Public Sale of Units Net of Offering Costs     $ 3 $ 3